Ennatosaurus tecton

Ennatosaurus is an extinct genus of caseid synapsid that lived during the Middle Permian (late Roadian - early Wordian) in northern European Russia. The genus is only represented by its type species, Ennatosaurus tecton, which was named in 1956 by Ivan Antonovich Efremov. The species is known from at least six skulls associated with their lower jaws (two of them preserved with the hyoid apparatus), as well as from the postcranial bones of several juvenile individuals. Ennatosaurus has the typical caseid skull with a short snout tilted forward and very large external nares. However, it differs from other derived caseids by its postcranial skeleton with smaller proportions compared to the size of the skull. As with other advanced caseids, the teeth of Ennatosaurus were well suited for slicing and cutting vegetation. The presence of a highly developed hyoid apparatus indicates the presence of a massive and mobile tongue, which had to work in collaboration with the palatal teeth during swallowing. With a late Roadian - early Wordian age, Ennatosaurus is one of the last known caseids (with Lalieudorhynchus from southern France).

==Etymology== Ennatosaurus tecton means "ninth carpenter lizard". The strangeness of the name of this synapsid is related to its very unusual origin since the genus and species names correspond to the translation into Greek of the meaning of the Russian names of the discoverers of the first fossils of this animal. The genus name is dedicated to Tatyana A. Devyataya (the feminine form of Devyatyi whose name means ‘ninth’ = "ennatos" in Greek) and of "saurus" meaning lizard. The species honors Mikhail Alekseevich Plotnikov (after the Russian plotnik, meaning "carpenter" = "tekton" in Greek).